“Why,” “Who,” “When,” “What” and “How”; Questions about the EPA Amalgam Separator Regulation: “Why” Dental Practices Require Amalgam Separators

Thank you for following us on Part Two of our Blog Series to help Dental Professionals navigate the tricky road to EPA Amalgam Separator Regulation and amalgam separator compliance. As mentioned in our previous Blog, “Introduction to the EPA Amalgam Separator Compliance Blog Series”, we will be discussing why Dental Practices are now becoming regulated in regards to their mercury discharge output.


We do not have to address the dangers nor effects of mercury being released into the environment, as it is common knowledge to cause adverse effects on both wildlife and humans. This blog is to explain why Dental Practices are now the new target industry for regulations (the EPA amalgam separator regulation). As most other industries have already been regulated, it is now the Dental Industry being recognized by the EPA, Water Treatment Plants, and other environmental agencies to be highest polluters of mercury waste.

Dental Industry: the Next Logical Industry for Regulation

According to a 2001 study completed by the EPA Mercury Pollution Prevention Study, quoted by OSHA Review Incorporated, it shows roughly 50% of mercury that is in our wastewater comes from Dental Practices; this can be seen in Image 1. This 2001 study, by the EPA, did not consider the effects mercury amalgam has on wastewater when it settles at Water Treatment Plants. In 2014, studies were released, providing evidence that the highest source of soluble mercury pollution comes from the mercury amalgam released by Dental Practices. As we all know, mercury amalgam contains tin, which has an ionic charge that releases mercury into its free state, which is a gas. When this mercury is submerged under water or any liquid, it releases into soluble mercury at a high rate, causing many Water Treatment Plants not to meet their mercury discharge limits. When the EPA took away Water Treatment Plants ability to dilute the water to meet mercury discharge limits, this made the Dental Industry the next logical choice to be regulated.

Mercury-in-waste-water-300x162Image 1

Amalgam Separators – Best Available Technology

Currently, there is an understanding that the best solution to capture mercury waste from the Dental Practice wastewater is with the use of an amalgam separator. Most first world nations around the world have already required the use of amalgam separators to reduce the mercury discharge from Dental Practices for well over a decade. A study completed by the Royal College of Dental Surgeons of Ontario (RCDSO), in 2002, had shown a considerable reduction in mercury pollution with the requirement of amalgam separators in Dental Practices (2002; pg. 26-27).

The RCDSO study did an excellent job explaining where the mercury waste was being generated, the size and percentage of mercury entering the amalgam separator and the reduction of mercury waste at the Dental Practice’s discharge. This study has found that a Dental Practice without an amalgam separator would release on average 31,297,300 ng/L (Parts per Trillion) of mercury into the sewer waste system.

Those Dental Practices tested with an amalgam separator reduced their discharge to 180,000 ng/L. This study showed a drastic difference in mercury discharge when a Dental Practice installs an amalgam separator and maintains them to manufacturer’s specifications.

There are two notable points regarding the RCDSO study. The first is that the City of Toronto has found that, over the years, roughly 70% of Dental Practices with amalgam separators do not maintain them to manufacturer specifications, leaving them non-compliant. Those Dental Practices who do service their amalgam separators correctly still is not guaranteed to meet the local standards. It is the experience of both the City of Toronto and the RCDSO that many ISO tested amalgam separators do not meet their advertised separation percentages in clinical environments (2002; pg.5-6). The second notable point, even though the RCDSO study was done very well, and did an amazing job at testing for solid mercury, in 2002, they lacked the technology to test for soluble mercury. A 2014 study completed in Ohio, by Purves Environmental, had found that majority of ISO tested amalgam separators generate and release soluble mercury, making it difficult for Dental Practice to meet their local standards (pg. 5).

Staying Compliant with the EPA Amalgam Separator Regulation

Amalgam Separators are still the Best Available Technology to reduce mercury discharge into our wastewater. Dental Professionals will have to be diligent when selecting the right amalgam separator to remain compliant. Please continue reading this Blog Series as we will be discussing how to choose the right amalgam separator that will guarantee compliance with your Local Control Groups. The next blog in this series will be discussing “Who” will be Regulating and Implementing the Amalgam Separator Regulation.



1. OSHA Review Incorporated- https://oshareview.com/2017/04/recommended-bmp-minimize-the-dissolution-of-mercury-in-vacuum-lines/ (cites Pie Graph, EPA Mercury Pollution Prevention Study, 2001, p. 1).

2. Watson P, Adegbembo A & Lugowski S – A Study of the Fate of Mercury from the Placement and Removal Of Dental Amalgam Restorations Final Report Part 1: Removal of Dental Amalgam Restorations 2002; p. 5-6; p. 26-27

3. Purves W. Dental Separator Study 2014; p. 5